Prediction of DSRC Service Over-reach inside an Arched Transportation Tunnel

Inside tunnels, the possibility of over-reach of radiated power from the Dedicated Short Range Communications (DSRC) service zone to the out-of-service zone is high, since the waves are confined in the tunnel space. To inspect this more carefully, wideband directional channel measurements were conducted inside an arched transportation tunnel, and the gain, angle-of-arrival and delay of each propagation path were estimated from the measured data. These propagation paths reveal that paths scattered from ground and sidewalk are the dominant factors that cause the over-reach of radiated power. This then suggests that the ground and sidewalk paths together with the LoS path can be used to predict the over-reach inside a typical transportation tunnel.